Question

The solar corona has a temperature of about \(1 \cdot 10^{6} \mathrm{~K}\). However, a spaceship flying in the corona will not be burned up. Why is this?

Short answer

Answer: A spaceship doesn't burn up in the solar corona due to the corona's low-density plasma and limited energy content, despite its high temperature. The low density results in minimal heat transfer from the corona to the spaceship, and the spaceship's thermal protection systems and heat shielding further protect it from the high temperatures.

Step-by-step solution

Understand Temperature

Temperature is a measure of the average kinetic energy of the particles in a substance. A high temperature means that the particles have a high average kinetic energy. However, high temperature does not guarantee a significant amount of heat transfer. The heat transfer depends on other factors, such as the density of the particles and the heat capacity of the substance.

The Solar Corona's Properties

The solar corona is an extremely low-density plasma, meaning that the number of particles per unit volume is very low compared to, for example, the Earth's atmosphere. The low density of the corona implies that the total energy contained within it is relatively low, even though the individual particles have high kinetic energy (high temperature). Therefore, the corona holds a limited amount of energy to transfer as heat.

Heat Transfer Mechanisms

The three main mechanisms of heat transfer are conduction, convection, and radiation. In the solar corona, heat conduction and convection are negligible due to the low density of particles. This leaves radiation as the primary mode of heat transfer. The emissivity of the plasma in the corona is also quite low, resulting in limited radiative heat transfer from the corona to the spaceship.

Spaceship's Protection

Spaceships are designed to protect against the harsh environment of space, including high temperatures. They have thermal control systems and heat shielding that reflect or absorb the incident heat from external sources like the solar corona.

Conclusion

A spaceship flying in the solar corona will not be burned up because the solar corona has a low density and limited energy content, despite its high temperature. The low density makes the heat transfer from the corona to the spaceship minimal. In addition, the spaceship’s thermal protection systems and heat shielding help to protect it from the high temperatures.